Method of mediating forward voltage drift in a sic device

Abstract

A method of reversing Shockley stacking fault expansion includes providing a bipolar or a unipolar SiC device exhibiting forward voltage drift caused by Shockley stacking fault nucleation and expansion. The SiC device is heated to a temperature above 150° C. A current is passed via forward bias operation through the SiC device sufficient to induce at least a partial recovery of the forward bias drift.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application claims priority to U.S. Provisional Patent Application Ser. No. 61 / 049,008, entitled “TEMPERATURE-MEDIATED FORWARD VOLTAGE DRIFT AND RECOERY TN HEXAGONEAL SILICON CARBIDE BIPOLAR AND UNIPOLAR DEVICES,” to Caldwell et al.TECHNICAL FIELD[0002]This invention relates generally to a method of mediating forward voltage drift in a SiC device, and, more particularly, to a method of at least partially recovering and / or inhibiting the forward voltage drift that occurs during typical forward bias operation of the SiC device.BACKGROUND ART[0003]Silicon carbide is a desirable material for high power and temperature bipolar and unipolar electronic devices, such as high blocking voltage PIN and Schottky diodes, respectively. Other such devices include, but are not limited to, junction barrier Schottky diodes (“JBS”), merged-PIN-Schottky diodes (“MPS”), double-diffused metal-oxide-semiconductor field effect transistors (“DMOSFETS”), verti...

AI Technical Summary

Benefits of technology

[0011]There are several advantages to one or more embodiments of the invention. First, the operation of the devices at elevated temperatures reduces the impact of SSFs upon the devices and minimizes the expansion of the SSFs and the corresponding Vf drift degradation rate and magnitude. This would allow devices that would otherwise be unacceptable for room temperature operation due to high BPD densities to become commercially viable for applications in high ambient temperature environments.

[0012]Current-induced induced recovery, the procedure of recovering the Vf drift via SSF contraction under forward bias operation within the above mentioned current and temperature specifications, for example, allows for the regeneration of electrically degraded hexagonal-SiC devices. This enables refurbishment of circuits and/or devices for further use, extending the operational lifetime of the devices, despite some level of SSF-induced electrical degradation having previously occurred. Furthermore, current-induced recovery within a circuit can be induced more readily and often, maintaining the devices within a given voltage tolerance for the turn-on voltage. Current-induced recovery would enable a

Problems solved by technology

Smaller currents typically do not provide sufficient recovery rates to be useful, where

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